Method of mothproofing pile fabrics



.March 25, 1947. J, N 'DOW METHOD 0F MoTHPRooFING PIL-E FABRICS XMMSPatented Mar. 25, 1947 METHOD OF Mo'rHPRooFING PILE FABRICS James N.Dow, Longmeadow, Mass., assigner to Bigelow-Sanford Carpet Co., Inc.,Thompsonville, Conn., a corporation of Massachusetts Application October31, 1941, Serial No. 417,277

Y (C1. 11i- 111) 7 Claims.

This invention relates to the mothproong of pile fabrics and its objectis to provide an economical treatment for impregnating all of the pileyarn, including the tuft and base portions thereof, of a continuouslyadvancing web of fabric with mothproofng agents of the substantive typewhich chemically combine with the wool molecule. My treatment issubstantially uniform from end to end of the web.

The preferred embodiment of my invention includes the consecutive stepsof impregnating the pile yarn with a substantive mothprociing agent inaqueous solution, steaming the impregnated fabric to eiect exhaustion ofthe agent onto the pile yarn, followed by drying. As will be described,the liquor application is effected in such a way, preferably by pressingand wiping the solution into the pile, as to force the liquor into thebase as Well as the tuft portions of the pile yarn without causing anysubstantial absorption of the liquor by the threads of thebackingfabric. Impregnation of the bases of the pile yarn is necessary foreffective mothproong, since the moth larvae tend to hide in the basesaway from the light, yet by avoiding excessive impregnation of thebacking threads I minimize waste, since those threads are of cellulosicmaterial not attacked by moth larvae.

My method of application obviates any material exhaustion ofmothproofing agent to the pile yarn until after the fabric leaves theliquor supply so that I insure maintenance of the liquor at asubstantially unvarying concentration and I thereby insure that a longweb of fabric receives a substantially unvarying amount of agent fromend to end of the web. A

By treating the pile yarn of a woven fabric, as contrasted with treatingthe raw wool stock, I effect substantial economies by avoiding the wasteof expensive mothproofing chemicals as the result of lost raw stock berduring the picking, carding, spinning, winding and weaving operationsnecessary to convert the raw stock into woven pile. As contrasted withmothprcoiing the spun yarn prior to weaving, I not only reduce waste butalso obviate the loss of bloom 0r tuft flare in the finished fabricwhich would result from adhesion together of the tuft fibers when theyare cut off during the weaving.

My treatment is therefore not only effective but inexpensive and I haveachieved this result even in Jacquard fabrics where the base of the yarnis buried between upper and lower layers of cellulosic weft.

In the drawing:

Fig, 1 represents diagrammatically apparatus which may effectively beemployed to carry out the treatment embodying my invention; and

Fig. 2 is a detail warpwise section of my novel mothprooed fabric.

The pile fabric 2, having pile 2a and a backing 2b, enters the machinearound idlers 4 and t,

being drawn in succession over a mothprooiing liquor application devicel, through a steamer l2 and a drier ll. The fabric is advanced in thedirection indicated by arrows by means of the rolls l5, 20 and 2t,having respectively spikes I8, 22 and 2'8 protruding from theirperipheries and adapted to engage and grip the backing 2b of the fabric.The spike rolls IE and 20 are driven from a power source Silwhose speedcan be varied to change the speed of advance of the fabric and which isconnected by chain 32 to a sprocket 3ft fixed to the shaft 3S to whichroll 2i) is securedl. A chain 38 passes aro-und sprocket lill alsosecured to shaft 35 and around another sprocket 42 iXed to shaft fifi,to which roll I6 is secured, to drive roll it from r-oll 2t. Spike rollsIt and 2! have the same peripheral speed. Spike roll 24 is driven froman independent variable speed power source Eii'by means of chain 52passing around sprocket lill iixed to shaft 56 tc which roll 2B issecured.

The applicator it consists of an application roll t@ immersed in a tankS2 containing' mothpro-ofing liquor 64 heated in any suitable manner,such as is indicated diagrammatically by the steam pipes t5. Theapplication roll 8&3 is secured to a shaft 'it to which is xed asprocket 'i2 driven by chain lil from a variable speed power source lt.

To press the pile 2a. of the fabric against the application roll Sil,the fabric passes around iders Si? and Si! which are so positioned withrelation to the uppermost portion of the periphery of the roll il@ as tocause the fabric to be deflected, as indicated, during its travel overthe roll. To increase such pressure I provide a tension device whichconsists of a roll having spikes adapted to engage the fabric andmounted coaxially with a brake drum il having a brake band I3 secured atl5 to the frame of the machine and connected at Il to the lever arm lilpivoted at 2l and having a weight 23 which may be adjusted lengthwise ofthe lever arm to vary the drag on the fabric and thereby increase ordecrease the pressure between the fabric and the periphery of theapplicaticn roll B3.

The application roll Si) is preferably rotated, as indicated by thearrow, in a direction contrary to the direction of advance of thefabric.

After the fabric leaves the application roll its pile rubs over apresser bar 9G, effective to press the liquor carried by the pile intothe pile and effect better penetration.

The fabric, while its pile yarn is wet with the inothproong liquor,immediately passes into steamer l2 filled with steam from a suitablesource, as indicated by the steam pipes itil. rEhe steamer may be of anydesired construction provided it is of sufficient length to effectadequate steamingcf lthe fabric as required to exhaust onto its pileyarn the mothproong agent carried in solution by it. I have showndiagrammatically a festoon steamer with festcon rods H32 advanced inconventional manner to convey a brake band 122 whose tension is madeadjust-y able by the weighted lever |24 just as described above inconnection with the tension roll 8.

From the tension roll |28 the fabric passes through drier I4 which maybe of any desired construction and into which hot drying air is suitablyadmitted, as indicated by the conventional hot air inlet I3!) and outlet|32. The length of the drier lil should, of course, be sufficient toeffect complete drying of the fabric before it emerges and passes aroundthe drive cylinder 2B to the next succeeding step in the manufacture, asindicated at |50.

The liquor in tank l0 comprises a solution of a mothproong agent of thetype which is substantive to wool. I may use any of the known types ofsuch agents but I prefer to employ pentachloro dihydroxytriphenyl-methane-sulphonic-acid of the nature available to the tradeunder the name Eulan CN. Another suitable material is an organicsilicoiluoride of high Inolecular weight available as Amuno. Still othersuitable materials ofV the substantive type may be used. Taking Eulan CNas typical, I shall describe my invention with respect to its use.

'The formula for a bath which I have used successfully in practicecomprises i ounce Eulan CN per gallon of hot water (180 F.) to which isadded .25% by weight, based on the combined Weight of Eulan CN andwater, of 56% acetic acid.

As the fabric 2 advances pile downwardly over the application roll Sliin the direction shown by arrows, the roll rotates in a reverse orclockwise direction. The pile tufts are wiped and somewhat iiattened bythe surface of the roll and the vigor of this wiping action isaccentuated by the pressure of the fabric against the roll resultingfrom its deflection, as indicated, going over the roll and the dragexerted by the tension device 8. My experiments have shown that betweenapproximately 11/2 and 2% of Eulan CN to the weight of wool exhaustedonto the pile yarn will effect good mothproong if distributedsubstantially uniformly over the tuft and base portions thereof, and inpractice 1 have employed approximately 11/2%. The quantity of mothproongliquor entrained by the yarn at the application roll, and sodistributed, is sufficient at the concentration 0f l ounce mothproongagent per gallon of hot water to effect, when subsequently steamed, theexhaustion of that required amount of agent onto the tufts.

To effect such entrainment requires not only that the fabric pressfirmly against the roll Gil but also that the fabric and roll rotate atthe proper speeds with relation to the construction of fabric beingprocessed. Thus, if the fabric to be treated consists, for example, ofl2 foot wide carpeting weighing 2.63 pounds persquare yard, of which1.18 pounds per square yard represents pile yarn, and assuming that thecarpet advances at a speed of 48 inches per minute so that i4.03 poundsof carpeting or 6.29 pounds of pile yarn per minute pass over theapplication roll, a reverse peripheral speed of advance of that roll of1270 inches per minute will deposit on the yarn approximately 1.65gallons of solution per minute which, when exhausted to the yarn, willincrease its weight by about 1l/2% allowing for slight absorption by thebacking threads. These values may, of course, be varied considerablyand, generally speaking, the faster the speed of rotation of the rollrelative to a given speed of advance of the fabric the more solutionwill be entrained by the tufts, and the faster the fabric is advancedthe greater must be the peripheral speed of the application roll todeposit a given amount of solution.

By so forcing the pile yarn to entrain a sufficient quantity of thesolution to eect the mothproong desired, I am able to remove the fabricfrom the supply of mothproong liquor before any material exhaustion ofthe agent on the yarn takes place. Thereby I insure that the mothproongliquor is not weakened materially during the mothprooi'lng of acontinuous web so thatv the quantity of agent exhausted to the pile yarnis substantially unvarying from end to end of the ness of impregnationof the mothproofing liquor throughout the fibers of the pile yarn,including both tuft and base portions thereof.

While the pile yarn is still wet with the mothproong liquor the fabricpasses through the steamer i2 to exhaust the mothproofing agent onto theyarn, such exhaustion being enhanced by the elevated temperatureresulting from the steam and by the acidity imparted to the liquor bythe acetic acid. In practice I have found that subjecting the fabric tosaturated steam at atmosnheric pressure or slightly above forapproximately 20 minutes will suffice to complete the exhaustion of theagent onto the wool yarn. The

steamer must, of course, be of sufficient length to satisfy, thenecessary requirements as to steaming time relative tothe speed ofadvance of the fabric.

After steaming, the fabric is immediately dried in the hot air drier i4where all of the moisture is removed. I prefer to keep the fabric undertension in the drier to obviate shrinkage. v

The completely dried fabric is then ready for the final steps inmanufacture, such as finish shearing and backing sizing. As shown inFig. 2,

`the fabric backing` 2b may conventionally be.

constructed of wefts 266 and 258. stuffer warps 282 and chain warps 20d.The pile yarn is composed of tufts 2a extending from the backing andbases 2b extending around the wefts Zim. Both the tuft portions 2a andthe bases 2b extending around the Wefts 293 are thoroughly impregnatedwith exhausted mothprooiing agent as indicated at Zeile and 2Mbrespectively. The drawing represents ideal conditions, and in practicethere would inevitably be some mothproofing agent in. the backingthreads as a result of capillarity. But a feature of my invention whichhas contributed largely to its success is that a large portion of themothproong agent is concentrated in the base portions of the pile yarnWhere the larvae hide, and this result has been attained by me inpractice even with Jacquard fabrics where theA bases of the yarn extendbetween layers of back-V plying the mothproong agent may serve for someneeds, such as by the use of an application -roll rotating in thedirection of -advance of the fabric. However, I greatly prefer to employthe method above described because it effects .'the;

base penetration required without excessive waste in the backingthreads. Furthermore, the concentration of agent in the liquor may beincreased above that which I have specified, employing for the purposeorganic solvents such as alcohols, ketones, ethers, esters and glycolderivatives. But in practice I have found that a normal concentrationsuch as that above described is entirely adequate.

I claim:

1. The method of applying a mothprooiing liquor to a pile fabric toimpregnato the pile in and through the base portions of said pilewithout substantial impregnation of the threads of the backing fabric,which comprises feeding the fabric continuously and in said feedingcompressing the pile to form a fiat layer of pile covering the threadsof said backing fabric, squeezing restricted quantities of a solution ofa substantive mothproong agent into said layer of pile and close to thebase portions of said pile, whereby said solution impregnates said baseportions, restricting the quantity of solution so applied so that nosubstantial amount penetrates through said layer of pile to enter thethreads l of the backing fabric, steaming said fabric while wet withsaid solution to exhaust said agent onto said pile and drying saidfabric.

2. The method of applying a mothproong liquor to a pile fabric toimpregnate the pile in and through the base portions of said pilewithout substantial impregnation of the threads of the backing fabric,which comprises feeding the fabric continuously and in said feedingflattening the pile to form a fiat layer with the ends of the pilepointed in the direction opposite to the direction of the feed of thefabric, applying restricted quantities of a solution of a substantivemothproong agent to said fiat pile layer and close to the base portionsof Said pile whereby said solution impregnates said base portions, whilerestricting the quantity of solution so applied to such limited amountsthat no substantial impregnation of the threads of the backing fabrictakes place, steaming said fabric while wet with said solution toexhaust said agent onto said pile and drying said fabric.

3. The method of applying a mothproong liquor to a pile fabric toimpregnate the pile in and through the base portions of said pilewithout substantial impregnation of the threads of the backing fabric,which comprises feeding the fabric continuously and in said feedingcompressing the pile to form a fiat surface against an applicator roll,squeezing restricted quantities of a solution of a substantivemothprooing agent carried `by said applicator roll into said fiatsurface and close to the base portions of said pile, whereby saidsolution impregnates said base portions, while restricting the quantityof solution so applied to such limited amounts that no substantialimpregnation of the threads of t'ne backing fabric takes place, steamingsaid fabric while Wet With said solution to exhaust said agent onto saidpile and drying said fabric.

4. The method of impregnating the pile only of a pile fabric, includingthe roots of the pile, with a mothproong liquor which comprisescontinuously feeding the fabric, rolling down the pile and resilientlysqueezing it to a flattened condition on the backing fabric andsimultaneously applying the liquor to the flattened pile and absorbingsubstantially all of the applied liquor into said pile.

5. The method of impregnating the pile only of a pile fabric, includingthe roots of the pile, with a mothproong liquor which comprisescontinuously feeding the fabric, rolling down the pile and resilientlysqueezing it to a flattened condition and simultaneously applying theliquor to the flattened pile in an amount approximately 11/2 to 2% ofthe weight of the pile yarn whereby substantially all of the appliedliquor is absorbed by saidpile.

6. The method of applying a inothproong liquor to a pile fabric toimpregnato the pile in and through the base portions of said pilewithout substantial impregnation of the threads of the backing fabric,which comprises feeding the fabric continuously and in said feedingcompressing the pile to form substantiaily a flat surface againstapplicator, applying restricted quantities of a solution of ainoothproofing agent carried 'by said applicator onto said flat surfaceand close to the base portions of said pile, whereby said solutionimpregnates said base portions, and regulating i quantity ofmoothprooiing agent applied by applicator in proportion to thecompression el the pile as determined by the tension of the web and itsrate of travelto insure application of a predetermined maximum quantityof mothproong agent essential to saturation of the pile structure butinsufficient to saturate the backing fabric.

7. The method of applying a mothproong liquor to a travelling pilefabric to impregnate the pile in and through the base portions of saidpile without substantial impregnation of the threads of the backingfabric, which comprises feeding the fabric continuously and in saidfeeding compressing the pile to form substantially a at surface againstan applicator roll, applying a solution of a mothproong agent carried bysaid applicator roll onto said flat surface and close to the baseportions of said pile, and regulating the speed of rotation of said rolland its direction of travel in proportion to the tension and relativespeed of travel of the fabric to insure a constant rapid application ofa predetermined o1uantit57 of mothproong agent essential to saturationof the pile structure and its base but insufficient to permit saturationof the backing fabric.

JAMES N. DOW.

REFERENCES CITED The following references are of record in the le ofthis patent:

UNITED STATES PATENTS Number Name Date 2,234,666 Bulford Mar. 11, 19412,184,147 Lowe Dec. 19, 1939 1,771,341 McCollum July 22, 1930 676,375Whipple June 11, 1901 545,420 Bamford Aug. 27, 1895 1,850,413 Porte Mar.22, 1932 2,163,104 Salzberg June 20, 1939 1,659,598 Funk Feb. 21, 1928FOREIGN PATENTS Number Country Date 484,991 British 1936 477,196 BritishDec. 23, 1937 OTHER REFERENCES American Dyestuff Reporter, vol. XIV, No.8, pages S22-323.

Textile Colorist, vol. 47, pages 229-231.

Chem. & Ind., Dec. 3, 1938, pages 1143-1146.

